Originally Posted by
Rixis
She was Anduins sister, so she was Taria Lothar.
That and Arthas' sister was called Calia (plus she'd be a similar age to varian i would think at this time).
Some searching puts Calia 4 years younger than Varian, so she'd be 6 year old in the movie (if she were in it).
For Taria Wrynn (assuming your second mention of menethil is also incorrect, not just the title) she's movie canon only, they could put her in the game, but have not yet done so, so it's not proper canon. That said, Metzen was part of her creation so they may come out and say she is/reference her ingame.